That's what I thought too, though it doesn't even need to be that much water. Just a reasonabily sized area walled off where I expect to land, then fill the rest with the highest value material possible. Or maybe a variety of different materials as to not deflate their value.

While I have little understanding of the actual servers hosting us, I suspect each of us get our own individual HDD for our personal data. Analogous to inside our current simulation, HDDs are very nice and efficient to fill at first, but over time get less so as fragmentation becomes an ongoing issue. Studies suggest that the 'meditation' subroutine may have its own defragger built in which can help alleviate some of the problem, but outside of it there doesn't appear to be any implementation of one.

Earlier players may have had more than one HDD as there were fewer people back then, so more resources could be allocated to each individual, which could be the reason for their extended lives.